Organic compounds serving as cya



Patented Mar. 3.0, 1948 ORGANIC COMPOUNDS SERVING AS OYA- NINE DYESTUFF INTERMEDIATES John David Kendall, Henry Walter Wood, and

John Raymond Major, Ilford, England, assign- ,ors to Ilford Limited, Ilford, Essex, England,

a British company No Drawing. Application'october 8, 1942, Serial 16 Claims.

This invention relates to the productionoi new organic compounds which are of value as intermediates in the manufacture of dyestuffs.

Processes arealready known'for the manu- In .GreafBritain November 6,

however, if a hydroxylic solvent is employed there results some hydrolysis of the compounds of general Formula I to the corresponding monoacylated compounds. In order to reduce as much facture of organic compounds of the general 5 as possible this tendency to hydrolysis-the re- Formula I: agents are preferably used as dry as possible. A very convenient acid to use is dry hydrochloric 14F OH: CH) (I) acid gas. Any excess 'of this remaining Jatthe. end of the reactionis capable of removal under R1 reduced pressure.

where D. isthe residueof a. heterocyclic nitrogen nucleus, R1 is an alkylor aralkyl group,'Rz and R3 are hydrocarbon groups, e. g..alkyl, aryl or aralkyl groups,.and nis noughtor 1. Such com phide or treating the. former compound with phosphorus pentachloride .and ,then with .thioacetarnide. It has been found that neither of these processes is'effectiverin converting compounds of general Formula Ito thecorresponding thione compounds.

It has now been discovered, however, and this forms the basis of the present invention, that compounds of general Formula I may be readily converted to corresponding compounds containing reactive t ioether groups by treating with an alkylor aralkyl-mercaptan in the presence of a strong acid. The reaction may be efiected in thepresenceof a solvent for thereactants;

The course of thereaction isbelieved to be -as follows. In these formulae A is an acid radicle, R'iS an alkyl or aralkyl group and the other symbols have the meanings assigned to them pounds maybe prepared byreacting an. alkyl or "above: aralkyl quaternary salt of a heterocyclic nitro- 3 gen compound containing an alkyl-thio group in I I the a or 'y positionto the heterocyclic nitrogen 1TT (OH OH)" C HA+R4SH atom with a 1.3-.diketone .ofthegeneral' Formula R1 0033 II:

R2.CO..CH2.CO.R3 (11) l in the presence of an-acid binding agent. Processes have also been described for converting compounds of the type of 1\;"'' "j B1 A COR: (III) C=CHC 0 CH: 1 N

D c to the corresponding th1o compounds of tne type r '1 BASH s 1 l (oH-orn,.=c-o R1 R1 A CORa (IV) o=orr-csom H20 1 (1H3 .---D----: SR4 These processes consist in directly heating- 40 =(O RBCOOH the former compoundwithphosphorus pentasul- R] R; (v

The applicants consider their new intermediates to have the general Formula V. It is clear that the reaction does not depend on an initial hydrolysis of the compound of general Formula I to the mono-acylated compound from the fact thattreatment of the mono-acylated compound with an alkyl mercaptan and an acid does not produce the thio compound, the original material being obtained unchanged.

The new intermediates of general Formula V may readily be isolated from any acylated products produced by hydrolysis of the compounds of general Formula I since the new intermediates are more soluble in ethyl and methyl alcohol. The new intermediates are quite stable in such alcoholic solution and evaporation of the alcohol under reduced pressure yields the intermediates in solid form.

Referring to the formulae set forth above, the

residue D may be the residue of any heterocyclic nitrogen compound, e. g. the residue of any of the heterocyclic nitrogen compounds commonly employed in the manufacture of cyanine dyestuffs such as the substituted and unsubstituted thiazoles, thiazolines, oxazoles, oxazolines, selenazoles, selenazolines, pyridine, quinoline, indolenine, diazines (e. g. pyrimidine) thio-diazoles and quinazoline and the corresponding sub-stituted or unsubstituted polycyclic compounds such as benzthiazoles, naphthathiazoles and anthrathiazoles and also the diazines described in specification No. 425,609, now Patent No. 2,366,222.

The groups R1, R2, R3 and R4 may variously be hydrogen atoms, alkyl, aryl or aralkyl groups as above defined. R1 is preferably a lower alkyl group, i. e. a methyl, ethyl, propyl or butyl group 7 or, if an aralkyl group, is preferably a benzyl group. R2 and R3 are preferably lower alkyl groups but they may be higher alkyl groups or aralkyl groups or aryl groups. The group R4 is preferably a lower alkyl group since the lower alkyl mercaptans are more easily reactive in the process of this invention, though it may be an aralkyl group. Any of the aforesaid alkyl, aryl or aralkyl groups may themselves contain substituent groups, e. g. hydroxy or amino groups.

As indicated above, dry hydrochloric acid gas is a very convenient acid to employ in the process of this invention. However, other strong acids may be employed, e. g. other hydrohalic acids, nitric acid, sulphuric acid, or phosphoric acid. or strong organic acids, e. g. p-toluene sulphonic acid.

The intermediates obtained by the process of the present invention are in the form of quaternary salts and it is to be understood that they may be converted to quaternary salts of other acids by treatment with suitable salts of such other acids, e. g. alkali metal salts. Thus intermediates obtained as chlorides may be converted to bromides or iodides by treatment with potas- V sium bromide or potassium iodide.

The dyestuff intermediates of this invention may be employed for the formation of dyestufis by condensing them with quaternary salts of heterocyclic nitrogen compounds of the type used in cyanine dyes (e. g. any of the heterocyclic nuclei hereinbefore mentioned) containing in the a or 7 position to the heterocyclic quaternary nitrogen atom a reactive methyl group, monosubstituted methyl group or external methylene group or by condensing them with heterocyclic nitrogen keto-methylene compounds (e. g. rhodanic acid, hydantoin, pyrazole-S-ones and oxindoles) or other cyclic keto-methylene compounds.

The following examples illustrate the inven-.- tion:

Example 1 Preparation of the dyestufi intermediate of the probable formula:

22.5 gms. of l-(diacetyl-methylene)-2-methyldihydro-benzthiazole, 50 cos. of methyl alcohol and 14 ccs. of ethyl mercaptan were mixed together and a stream of dry hydrochloric acid gas was passed through the mixture. The solid material in suspension slowly dissolved and when It had a melting point of C.

Example 2 Preparation of the dyestuif intermediate of the probable formula:

I can I CH3 01 14.7 gms. of 1(benzoyl-acetyl-methylene) -2- methyl-dihydro-benzthiazole, 50 ccs. of methyl alcohol and 20 ccs. of ethyl mercaptan were mixed together and dry hydrochloric acid gas was passed through the mixture. The suspended solid matter slowly dissolved. After about one hour a yellow solid was precipitated and this consisted of the hydrochloride of 1-(benzoyl-methylene)-2- methyl-dihydro-benzthiazole formed by partial SCzHs 'hydrolysis of the original benzthiazole compound.

It was separated by filtration and the filtrate was evaporated to dryness under reduced pressure. The solid residue was triturated with a little methyl alcohol and then filtered. On evaporation of the methyl alcohol from the filtrate the desired dyestuif intermediate was obtained as an orange yellow solid melting at C.

Example 3 Preparation of the dyestuff intermediate of the probable formula:

9 gms. of 1-methyl-2-(diacetyl-methylene)-1:2- dihydro quinoline and 50 ccs. of ethyl mercaptan were mixed together and cooled. 2.7 gms. dry

hydrochloric acid gas was then passed through the mixture. An oil separated on standing and this was separated and dried in a vacuum desiccator, yielding the desired dyestuff intermediate as a light brown sticky solid.

Example 4 Preparation of the dyestufi intermediate of the probable formula 30 gms. of 1- (w-dipropionyl-methylene) -2-methyledihydro-benzthiazole were mixed with 50 .ccs.

ofethyl mercaptan and 8 gms. of dry hydrochloric acid gas was passed throughtthe mixture. A yellow solid wasaprecipitated. The mixture was allowed to stand for-2.:da-ys, filtered and the excess mercaptanremoved from the filtrate by distillation, leaving the desired dyestufi intermediate as a yellow oil which solidified to low-melt- .ingzyellow needles.

"Example 5 Preparation of the'dyestufi'intermediate of'the probable "formula:

'7 gms. of Z-(diacetyl-methylene) -1.3.3.-trimethyl dihydro-indolenine and 25 t cos. of ethyl mercaptan were mixed togetherand 2 gins; of dry hydrochloric acid gas was-passed through the mixture. The mixture was'then left to stand. The

= product separated asan-ioil, which-was dried in a vacuum desiccator.

What we claim: is:

1. -A process 'for the production of dyestuff intermediates which comprises reacting a compound of the generalformula:

*wh'ereD is theresidueof a heterocyclic nitrogen compound of the type used. in cyanine dyes, R1 is selected from the class consisting of alkyl and aralkyl groups, R2 and R3 are hydrocarbon groups, and n is selectedfrom the class consisting of nought and 1 with asu'bstance selected from the class consisting of alkyl and aralkyl mercaptansin the presence of a strong acid.

- 2. process for t'heproduction of dyestufiin- I term'e'diateswhich comprises reacting a compound of the=-general formiila:

where D is'therresidue"ofaeheterocyclic nitrogen compound of the type used in cyanine dyes, R1

is selected fromlthe 'classzconsitsing of alkyl and aralkyl groups, R2 and .Rs arehydrocarbon groups, and n is selected fromuthe..class onsist ing of nought and 1 with a substance selected from the class; consisting: of alkyl and aralkyl mercaptans, in the presence of a strongtmineralacid.

, 3. A. process tor the production of dyestuff inatermediatest which comprises reactinga ;compound of the general formula:

where D is themesidue of a" heterocyclic nitrogen 7 compound of the type used in cyanine dyes, R1

.isrselect'ed from the lass consisting ofhalkyl and aralkyl groups,Rz and R3 are hydrocarbon groups, and n is selected from the class -consisting of noughtand l 1' with axsubsta-nce selecteddrom'the tclasscons isting oft alkyl and aralkylmercaptans inthepresence of dryhydrochlori acid gas.

-4. Afiprocessior the production of dyestuff intermediates which comprises reacting a compound of 1 the general formula:

, in com where D is the residue of a heterocyclic nitrogen compound of the type used in cyanine dyes, R1 is selected from'the classeonsisting-eof alkyl and aralkyl groups, R2 and R3 are hydrocarbon groups, and n is selected from the class consisting of nought and 1 with a lower alkyl mercaptan in the presence of a strong mineral acid.

, 5. A process for the production of, dyestuff intermediates which .comprisesrreacting a. compound of 1 the general formula:

where D is the residue of a heterocyclic nitrogen compound ofxthetype :used in cyanine dyes in which the onlyheterocyclic atoms arenitrogen,

R1 is selected from'the class consisting of alkyl and aralkyl groups, R2 and R3 are hydrocarbon groups, and n is selected fromthe class consisting of nought and 1 with a substance selected from the class consisting of alkyl and aralkyl mercaptans in the presence of a strong acid.

6; A :processxzfor the production of dyestuff :intermediates which comprises reacting acompound of the general formula:

where Dis the residue of a heterocyclic nitrogen compound of the type used in cyan-ine dyes in whichthe onlyheterocyclic-atoms are nitrogen,

R1 is selected from the'class consisting of alkyl and aralkyl gr0ups,'R2 and-R3 are hydrocarbon groups and n is selected from the class consisting of nought and lrwith a'substance selected from the class consisting of alkyl and aralkyl mercaptans,. in the presence of a strong mineral acid.

7. A .process for the production of 'dyestufi' intermediates which comprisesreacting a com pound of the general formula:

Where-D is the residue of a heterocyclic nitrogen compound of the type used in cyanine dyes in "which'the only heterocyclic atoms are nitrogen,

intermediates .whicbcomprises reacting a compound of the general formula:

where D is the residue of a heterocyclic nitrogencompound of the type used in cyanine dyes in which the only heterocyclic atoms are nitrogen, R1 is selected from the class consisting of alkyl and aralkyl groups, R2 and R3 are hydrocarbon groups and n is selected from the class consisting of nought and 1 with a lower alkyl mercaptan in the presence of a strong mineral acid.

9. A process for the production of dyestufi' intermediates which comprises reacting a compound of the general formula:

where D is the residue of a heterocyclic nitrogen compound of the type used in cyanine dyes in which the only heterocyclic atoms are nitrogen, R1 is selected from the class consisting of alkyl and aralkyl groups and n is selected from the class consisting of nought and 1 with a substance selected from the class consisting of alkyl and aralkyl mercaptans in the presence of a strong acid.

10. A process for the production of dyestuif intermediates which comprises reacting a com pound of the general formula:

where D is the residue of a heterocyclic nitrogen compound of the type used in cyanine dyes in which the only heterocyclic atoms are nitrogen, R1 is selected from the class consisting of alkyl and aralkyl groups and n is selected from the classconsisting of nought and 1 with a substance selected from the class consisting of alkyl and aralkyl mercaptans, in the presence of a strong mineral acid.

11. A process for the production of dyestuff intermediates which comprises reacting a compound of the general formula:

where D is the residue of a heterocyclic nitrogen compound of the type used in cyanine dyes in which the only heterocyclic atoms are nitrogen, R1 is selected from the class consisting of alkyl and aralkyl groups and n is selected from the class consisting of nought and 1 with a substance selected from the class consisting of alkyl and aralkyl mercaptans in the presence of dry hydrochloric acid gas.

12. A process for the production of dyestuff intermediates which comprises reacting a compound of the general formula:

where D is the residue of a heterocyclic nitrogen compound of the type used in cyanine dyes in which the. only heterocyclic atoms are nitrogen, R1 is selected from the class consisting of alkyl and aralkyl groups and n is selected from the class consisting of nought and 1 with a lower alkyl mercaptan in the presence of a strong mineral acid.

13. A dyestuff intermediate of the general formula:

wherein R1 and R4 are each selected from the class consisting of alkyl and aralkyl groups, R2 is a hydrocarbon group and X is an acid radical and the acyclic carbon atom is attached to a carbon atom of the hetero ring in a position taken from the group consisting of alpha and gamma positions to the nitrogen atom.

14. A dyestuff intermediate of the general formula:

wherein R1 is selected from the class consisting of alkyl and aralkyl groups, X is an acid radical and the acyclic carbon atom is attached to a carbon atom of the hetero ring in a position taken from the group consisting of alpha and gamma positions to the nitrogen atom.

15. A dyestufi intermediate of the formula:

16. A compound of the following formula REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Kendall Apr. 11, Brooker Feb. 6, Brooker Feb. 11, Brooker Mar. 4, Davey Nov. 25, Carol Mar. 16, Mareis Apr. 13, Kendall Aug. 15,

FOREIGN PATENTS Country Date France Sept. 1, 1942 OTHER REFERENCES Imperial Acad. of Japan (1937-1938), page 262.

Number Number Certificate of Correction Patent No. 2,438,?04. March 30, 1948.

JOHN DAVID KENDALL ET AL.

It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Column 2, lines 16 to 19 inclusive, for that portion of the formula reading con, I 00R,

read COR: COR: column 4, lines 50 to 55 inclusive, Example 3, for that portion of the formula reading 0-011 read CH column 5, line 55, for consitsing read consisting; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 15th day of June, A. D. 1948,

THQM'AS F. MURPHY,

Assistant Commissioner 0 f Patents. 

